Son of Dracula(1943)

Katherine “Kay” Caldwell (Louise Allbritton) is a southern belle obsessed with occultism and death, to the worry of her sister Claire (Evelyn Ankers) and fiance Frank (Robert Paige). She has invited the mysterious Count Alucard (Lon Chaney, Jr) for a visit after meeting him in Budapest where she picked up this strange obsession.

Old family friend Dr. Brewster is suspicious of Alucard and quickly divines his true name – Dracula!

Dr. Brewster calls in an expert from Transylvania, Professor Lazlo to help him get rid of Dracula. It is too late though for Kay and Alucard elope one night and are married. Frank, who has loved Kay since they were children is furious and takes a gun and shoots Alucard. The bullets pass harmlessly through him and strike Kay, who collapses dead. Frank runs off, horrified at what he has done and ends up at Dr. Brewster’s house, hysterical and exhausted.

Brewster drives out to Kay’s place and finds her very much alive.

The next morning Frank turns himself in for Kay’s murder. Brewster explains he saw Kay alive and spoke to her after Frank claimed he killed her, but in searching the grounds where Frank ran from the house they find Kay’s corpse, lying in a coffin in an abandoned cottage.

Frank is arrested for Kay’s murder and left in a cell overnight, where he is visited by Kay. Kay explains her plan was to become immortal with Dracula’s assistance and begs for Frank’s help in killing Dracula so that she can turn Frank immortal and they can live together forever. Frank swears to help her and she assists him in breaking out of prison.

Brewster and Lazlo are hot on Dracula’s trail and come to the jail to ask Frank if he knows where Dracula’s resting place is, only to find he’s escaped. The guard overheard Kay talking to Frank and is able to give Brewster enough info that he can follow Frank to Dracula’s coffin.

Frank makes it to Dracula’s coffin just before daylight and sets it on fire, and Dracula dies as the sunlight hits him.

He then runs off to meet Kay as they arranged, with Brewster and Lazlo one step behind. As Brewster and Lazlo catch up to Frank at his and Kay’s meeting-place, they find he has set Kay’s coffin ablaze, with her in it.